Loans - Impaired Loans - Average Recorded Investment and Interest Income Recognized (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Loans [Line Items]
Impaired Financing Receivable, Average Recorded Investment	$ 32,852	$ 35,057
Impaired Financing Receivable, Interest Income, Cash Basis Method	96	161
Commercial and Industrial [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	3,189	5,534
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	12	83
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	5,113	4,339
Owner-Occupied [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	6,425	7,487
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	3	18
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	1,125	1,265
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	4	5
Food and Agriculture [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,220	1,259
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	1	6
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	961	2,126
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method		1
Energy Loans [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	777	2,353
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method		20
Commercial Loan [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	11,611	16,633
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	16	127
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	7,199	7,730
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	4	6
Commercial Construction [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,208
Commercial Acquisition/Development [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	117	886
Multifamily [Member]
Loans [Line Items]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment		29
Non Owner-Occupied [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	546	876
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method		4
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	566	196
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	9	2
Total Commercial Real Estate [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	1,871	1,762
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method		4
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	566	225
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	9	2
Senior lien
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	4,325	1,612
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	2
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	5,629	5,601
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	25	13
Junior lien
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	363	305
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	1,205	1,151
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	40	9
Residential Real Estate Segment [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	4,688	1,917
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	2
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	6,834	6,752
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	65	22
Consumer [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	11	14
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	72	24
Impaired Loans With No Related Allowance Recorded [Member] [Member]
Loans [Line Items]
Impaired Financing Receivable, with No Related Allowance, Average Recorded Investment	18,181	20,326
Impaired Financing Receivable, with No Related Allowance, Interest Income, Cash Basis Method	18	131
Impaired Loans With Related Allowance Recorded [Member]
Loans [Line Items]
Impaired Financing Receivable, with Related Allowance, Average Recorded Investment	14,671	14,731
Impaired Financing Receivable, with Related Allowance, Interest Income, Cash Basis Method	$ 78	$ 30